Vacuum release mechanism for refrigerated cabinet



Oct. 22, 1957 R. l EICHHORN E VACUUM RELEASE flECHANISM FOR REFRIGERATED CABINET Filed May 11', '1955 2 Sheets-Sheet 1 jzzflentons: Rol art Z. fi'cfiborn Richard 'Ve'rdz'c% Oct. 22, 1957 RQL. EICHHORN Er L 2,810,493

VACUUM RELEASE MECHANISM FOR REFRIGERATED CABINET Filed May 11, 1955 2 Sheets-Sheet 2 If w "i In anions: R0500 1;. Eckfiorn v z'charcl .D. T erdz'cl United States Patent VACUUM RELEASE MECHANISM FOR REFRIGERATED CABINET Robert L. Eichhorn and Richard D. Verdick, Evansville,

Ind., assignors, by mesne assignments, to Whirlpooi- Seeger Corporation, a corporation of Delaware Application May 11, 1955, Serial No. 507,617

1 Claim. (Cl. 220-44) This invention relates generally to refrigerated cabinets, but is more specifically directed to a vacuum release of pressure equalizing means applicable for incorporation in such cabinets.

There is in wide use on the commercial markets today a low-temperature refrigerated cabinet, commonly referred to as a vertical freezer, wherein the cabinet and food storage area are usually arranged with a front access opening that is covered with a hingedly mounted door or closure member, and such freezer cabinet most generally is adapted for maintaining temperatures in the order of zero degrees Fahrenheit therein. In order to economically maintain such low temperatures in these cabinets over appreciable lengths of time it was found necessary to minimize air leakage around the access opening thereof and, accordingly, a very efficient and highly effective gasket seal was developed. However, the application of such highly effective air sealing means forthwith introduced a new problem involving the release or opening of the door because of pressure differences between the interior and the outside atmosphere, and the solution of such problem forms an important feature of the present invention.

It has been found that when a vertical freezer cabinet of the type mentioned is either empty or nearly empty that the pressure differential between the interior and the exterior of the cabinet thereof may become suificient to preclude or at least render difficult the reopening of the access or entry door immediately after it has been closed. It is believed this condition is brought about by the fact that when the door is opened the cold (zero degree) air in the cabinet falls out into the atmosphere, and then when the door is reclosed and the warmer air from the atmosphere outside the cabinet is forced thereinto the warm air immediately starts cooling and upon cooling contracts, thus reducing the pressure therewithin and forming a vacuum which must be overcome, preferably by equalizing interior and exterior pressures, before the door can again be readily opened. It was found in laboratory tests that it usually will require from five to six minutes before the air pressures inside and outside the cabinet are sufficiently equalized, through natural leakage of air around the sealing gasket and otherwise, to again permit easy opening of the door. At times, of course, such a delay becomes a definite nuisance as well as an exasperating inconvenience because the user thereof has to wait through the time of this pressure equalizing cycle to again gain entrance to the freezer. This would be particularly disturbing if some food article that should have been put into the freezer, such as one that required maintenance at a critical temperature to avoid spoilage, was inadvertently left out when the door was last opened. The present invention is directed to a novel solution of this unusual but heretofore not generally understood problem.

It is an important object of the present invention, therefore, to provide novel and simplified means for rapidly equalizing air pressure differences between the interior and exterior of refrigerated cabinets.

Another object is to provide pressure equalizing means between interior and exterior cabinet air pressures in a front opening type of refrigerated cabinet having a closure door hingedly mounted over said opening.

A further object is to provide a pressure-equalizing device incorporated in the door of a refrigerated cabinet and which cooperates with the door actuating handle mechanism to permit equalization of air pressures between the interior and exterior of the cabinet.

A still further object is to provide an air passageway communicating with the interior and exterior of a refrigerated cabinet and to additionally provide means whereby said passageway may be selectively opened or closed to the passage of air from outside said cabinet.

A yet still further object is to provide means for admitting air under atmospheric pressure into the interior of a refrigerated cabinet in order to minimize the air pressure differential between the interior and exterior of said cabinet.

The foregoing and other objects and features of the invention will become apparent as the disclosure is more fully made in the following detailed description of a preferred embodiment of the invention and as illustrated in the accompanying sheets of drawings in which:

Figure 1 is a front elevational view of a refrigerated cabinet employing the proposed invention;

Figure 2 is a top plan view of the refrigerated cabinet shown in Figure 1;

Figure 3 is a partial sectional view taken on line 3-3 of Figure 1 and shows generally the sealing means between the cabinet and the entry door;

Figure 4 is a partial sectional view taken on line 4-4 of Figure 1 and shows the application of a preferred embodiment of the proposed device to the door of a refrigerated cabinet; and

Figure 5 is a view similar to Figure 4 but shows a modified application of the present invention.

A reference to the drawings Will show that in the preferred embodiment selected for illustrating a general application of the present invention there is depicted an upright type of front-opening refrigerated cabinet which is represented generally by the numeral 10. This type cabinet usually is fabricated with an inner shell or liner 11 spaced from a similarly conformed outer shell or liner l2 and having heat insulating material 13 therebetween, while the marginal edges of said inner and outer shells may be bridged with a breaker strip 13a of any suitable well-known low-heat conducting plastic material as is well understood. The inner liner 1]. is formed to define a food storage area or compartment, indicated generally by the numeral 14, having a, front access opening thereinto that is covered by an insulated entrydoor 15 which may be hingedly secured to the cabinet by suitable means such as the hinges 16. The double-walled access door 15 may be fashioned somewhat similarly to that of said cabinet with an outer panel 17 spaced from an inner panel 18 and having heat insulating material 19 in the space therebetween.

The marginal edges of the outer panel 17 of said door may be secured by suitable conventional affixing means to a peripherally extending channel-like member 20, whereas the marginal edges of the inner panel 18 extend into a resilient gasket sealing member 21 and are suitably secured along with said gasket, by conventional means such as the screws 22, to said channel member. If desired, a suitable trim member, such as the resilient member shown at 23, may be positioned in a peripherally extending recess or opening 24 adjoining the forward marginal edge of the channel member 20. i i 7 Since the refrigeration apparatus plays no particularly- Patented Oct. 22, 1957 unusualv role in the present inventionit was not .shown in the drawings and will notbe described herein. Suffice it to say however, that any conventional or well-known refrigeration systemand apparatnslmay b e-used its normal manner-without deviating from anyteachingsor conceptsof the instantinvention. i

The door 15' is provided: withza= handle.25z pivotally mounted onathe exterior thereof, which:is -adapted:tozactuate a generally. conventionallatchingi mechanism. indie cated generally bythe referencemumerallo, that engages and interlocksg with a strike '27t which, in turn, is alfixed tothe: cabinet An escutcheon-like frame; or. guard rim 28ahaving an opening29 therein istsuitablypositioned over an opening provided in theinner, door panel meme ber-1Srin-the vicinity. ofthesaid latching mechanism. The opening. 29%in, said. escutcheon: is provided. to, accommodate the-strikeflswhich is suitably and adjustably secured,.asby.'the;scram 5 30, to apedestal-like spacer memher'lalithati is fixedly secured byconventional means toa'; transverse supporting member '32. which, in turn, is rigidly: fastened; by conventional. means. such as the screws 32a. between: the. inner. and. outer wall members 11: and t12;.respectively,.of said cabinet. The pedestallike support member 31 of said latch strike is dimensioned to: project; through; an opening in the; breaker strip member- 13a, and, if. desired, an escutcheonelike frame 33 may be positioned therearound for. appearance. improving purposes.

The latching device 26,,which is. a generally-available item on the commercial markets, is;fashioned with an outer casing orhousing;34 which supports and-encloses a-plurality of pivotally mounted and sequentially motivated operating or latch members 35, 3 6, 37 and 38. The latch casing 34 may be fixedly'positioned within the door, by; suitable. means; such; as the: screws 39, While a resilient gasket-like sealing pad 40 may be positioned between-said casing and the outer door panel 17. An actuating plunger 41 actuable by the handle 25- is slidablymounted in a bearing member 42 that is suitably secured to the door over an opening in the outer panel tioned between the said casing and said outer door panel,

is positioned over the adjoining openings in said door panel and casing and closely surrounds the plunger 41 so as to permit a sliding action thereof While at the same time sealing the area around said plunger against the admission of air from outside of said cabinet to the interior thereof. The handle 25 which is pivotally mounted on the pin 43 has a heel-like portion 44 which is disposed to contact and engage the outer end of the plunger 41 upon movement of said handle. A resilient restraining member, such as the spring 45, is disposed to'bias the handle to a position normally out of engagem'ent with said plunger. Mounted on a portion of the handle, disposed on the opposite side of the pivot 43 from that of the heel 44, is a button-like sealing pad member 46 which is positioned to seat on and to seal off or close the opening 47 through the door outer panel 17 together with the aligned opening 48 in a Wall of the latch housing 34. An opening 49 in an opposite Wall of said latch housing is provided to accommodate the latch strike 27 which engages the holding or interlocking roller 50 that is pivotally mounted on the latch member 38 forming part of the said latch mechanism.

In operation, when the door is closed the gasket seal, 21 engages and presses against the, flanged over marginal edge portion of the cabinet outer wall 12 and thereby provides an air seal againstthe ingress and egress of air to and from the food storage compartment 14. the. air within said compartment subsequently cools it contractsand a pressure differential is established between the cabinet air and that of the outside atmosphere; hence the subsequent breaking of the air seal provided by the gasket 21 is ordinarily accomplished only with great difficulty. With the present invention however, as the door handle 25 isv grasped by the user and rotated around the pivot. 43 to start the door opening operation the sealing button'46 is unseated by being raised off the opening 47 and, because'the atmospheric air is at a higher'pressurethanthat of. the compartment 14, air from outside the cabinetwilhfiow, in the path indicated generally by the broken arrow lines of Figure-4, through the aligned openings 47 and 48, through the interior of the housing 34 and the opening 49 in the opposite side thereof, and through-the opening 29 in the inner door panel 18 to the reduced pressure areas within said cabinet. The inrush of air at atmospheric pressure intocthe cabinet .tends t'o: raise, the: pressure therein and thus equalizes the interior'and exterior pressures. In this; way the: pressure. differential between ,the compartment or cabinet air and the outside atmosphere is minimized and; thus.thevacuum like ;eifect of the air seal is brokeniandthe door.- maythenbe easily opened. By Colltllllllnggthfl rotation otthe handle.25 aboutits pivotal mountingrjpin 43, the. heel 4.4. of said handle ismade to engage;-and; actuate; the plunger: 41: which, then slides. in its bearing,memb 1':42:to contact thefirstlatch operating member" 350i the latchmechanism 26. The motion transmitted by said plunger to member 35, in turn, is transmitted successively through members 36 and 37 to the last member 38 whichupon. rotation releases the keeper, ofholding roller 50 fromits interlocking relationship with'the strike 27; thereby permitting the door tobe opened. Since the latching mechanism is generally conventionalin construction it isfelt further. detailed description of. thecomponents of its structure, and operation is unnecessary for purposes of the presentinvention.

In Figure 5- there-is illustrated a modified application of the present invention. In order to simplify: details of description all similar parts of the. cabinet; and door. structure have. been designated withthe same reference numeralson both thepreferred and modified embodiments; hence a repetition of the details thereof in the description is felt to be unnecessary. A modified latch mechanism, indicated generally by the reference char.- acter 51, has an outer casing or housing 52 which encloses the sequentially motivated operating or latchmembers S3, 54, 55 and 56, and said housing may be secured between the walls of the door, by suitable conventional means such as the screws 57, with a suitable resilient sealingpad-57a interposed'between said housing and the. outer door panel. A holding roller; or keeper member 58 isv pivotally affixed to the operatingv member 56 and saidroller isadapted to interlocking engage the latch strike 27 for retaining the cabinet door tightly closed. An: actuating plunger 59; is slidably mounted in a slide bearing 69, formed as part of an escutcheon-like frame. member 61 and secured by suitable conventional means (not shown) to the outer door panel 17. Pivotally mounted on said escutcheon-like frame as by the pin 62 is a handle 63. which, upon rotation, is disposed to actuate the plunger 59. A. spring member 64 suitably anchored around the pin 62 abuts atransversely disposed pin 65 in the-plunger 59-and as so-arranged serves tobias said plunger into. a position such that one end thereof constantly engages the handle.63 and urges it to the position indicated in the drawing by the solid lines for said handle. At theijsame time the opposite, end of said plunger is positioned so flsnot to exertany. appreciable forceon the first latch operating member 53 of said latch mechanism. Attached'to the plunger 59 and adapted for movement therewith is a valve-like disc '66 having a ring-like gasket seal 67 affixed to one face thereof. The plunger 59; extends successively through aligned openings in the door-panel 17, the'sealing pacl57a and the side wall of the latch housing 52 but because of the many details and the small scale of the drawings these openings, which are all adjoining and registering one with the other, are indicated as a group by the single reference numeral 68. An opening 69 in the base of the escutcheon frame 61 is disposed so that a large portion of the area thereof overlies the adjacent group of aligned openings 68, while and opening 70, in an opposite side wall of the housing 52, is provided to admit the latch strike 27 into said latch mechanism where it may engage the interlocking roller 58.

In operation, the modified embodiment is quite similar to that of the preferred embodiment and as the door 15 is closed the gasket seal 21 engages the flanged over marginal edge portion of the cabinet outer wall 12 and provides an air seal against the entrance and exit of air to and from the food storage compartment 14. As previously mentioned when the air within the said compartment subsequently cools and contracts it establishes a pressure differential between the interior and exterior of the cabinet which makes it difficult to open the door immediately after it has been closed. In the modified embodiment of the invention as the door handle 63 is grasped by the user and rotated around the pivot pin 62 to start the door opening operation the ring-like sealing gasket 67 is unseated and is raised off the group of openings 68 and, because the atmospheric air pressure is greater than that of the cabinet interior or compartment 14, air from outside the cabinet will flow thereinto. When the sealing ring 67 is unseated outside air is free to fiow through the opening 69 in the escutcheon frame 61, through the adjacent group of openings 68 and into the interior of the latch casing or housing 52. After passing through said casing the air is free to pass through the opening 70 in the opposite wall thereof, thence through the opening 28 in the guard frame 29 and into the cabinet. The incoming air at atmospheric pressure tends to raise the pressure within said cabinet and eventually this is equalized with that outside the cabinet and the vacuum-like effect of the air seal is broken and the door may easily be opened. By continuing the rotation of the handle 63 about its pivotal mounting 62 the plunger 59 slides through its bearing 60 and contacts the first operating member 53 in the latch mechanism 51. The motion of member 53, in turn, is imparted to members 54, 55 and 56 which latter member then rotates to release the roller 58 from its interlocking relationship with the latch strike 27 and the door becomes free to open. The modified latc-h mechanism in- 6 dicated at 51 is generally conventional in construction and hence it is felt further detailed description of its structure and operation is unnecessary to a complete understanding of the operation of the instant invention.

It should now be apparent that a novel pressure equalizing means has been shown and described, and it is to be understood that changes may be made in the construction without departing from the spirit of the invention or the scope thereof as defined in the appended claim.

What is claimed is:

In a combined refrigerator latch mechanism and air pressure release, the combination of a hook shaped latch strike to be carried by a refrigerator adjacent a door opening, said strike having a transverse retaining shoulder and a beveled camming surface, with a latch and pressure release mechanism, comprising a support to be carried by the door, said support having a pivoted latching lever provided with a roller for engaging said beveled camming surface on said strike, to retract said roller, and said roller also being located to engage behind said transverse shoulder to hold the door closed, a handle lever pivotally mounted on said support, and having a handle end to move in the door opening direction to release said latch, a slidable plunger extending through said support for actuating said latch, said plunger being engaged at its outer end by a part on said handle to be moved inward to unlatching position, spring means biasing the mechanism toward the latched position, operative mechanical connections between the inner end of said plunger and said pivoted latching member, to unlatch the latter on inward movement of said plunger, and air valve means closing an air port extending through said support and door, and adapted to be opened first by said handle in the unlatching movement thereof, to relieve air pressure differentials on opposite sides of said door before releasing said latch, said air valve means comprising a closing disc having a resilient gasket mounted on said plunger and located to cover said air port, which is adjacent said plunger.

References Cited in the file of this patent UNITED STATES PATENTS 844,272 Fate Feb. 12, 1907 2,109,002 Warren Feb. 22, 1938 2,341,416 Anderson et al. Feb. 8, 1944 2,425,816 Maxson Aug. 19, 1947 2,698,197 Jacobson Dec. 28, 1954 

